Many types of machines have protective coatings applied to interior components of the machines. For example, turbine engines may have thermal barrier coatings (TBC) applied to blades, nozzles, and the like, on the inside of the engines. These coatings can deteriorate over time due to environmental conditions in which the engines operate, wear and tear on the coatings, etc. Unchecked deterioration of the coatings can lead to significant damage to the interior components of the engines.
The outer casings or housings of turbine engines usually do not provide large access openings to the interior of the casings or housings. Because these coatings may be on the surfaces of components on the inside of the engines, restoring these coatings can require disassembly of the engines to reach the coatings. Disassembly of the engines can involve significant expense and time, and can result in systems relying on the engines (e.g., stationary power stations, aircraft, etc.) being out of service for a long time.
Some spray devices that restore coatings can be inserted into the small openings in the casings or housings without disassembling the engines, but these spray devices usually operate by moving the spray devices or components in the spray devices in order to apply the different components of the coatings. This movement can be difficult to control and can make it very difficult to apply an even, uniform restorative coating on interior surfaces of the engines.